//timer circuit tester, this code makes the LED blink every time 
//the output of the timer changes.  With a timer circuit with a 
//10 micro F cap and two 10 kohm resistors the output of the timer
//changes 0.118 seconds

int pin = 13;
volatile int state = LOW;
volatile int count = 0;

void setup()
{
  pinMode(pin, OUTPUT);
  attachInterrupt(0, blink, CHANGE);
}

void loop()
{
  digitalWrite(pin, state);
}

void blink()
{
  state = !state;
  count++;
  if (count > 1000){
    detachInterrupt(0);
  }
}
